Differences in the epidemiology between paediatric and adult invasive Streptococcus pyogenes infections

A Striking Increase in Carriage Among Young Children in Iceland Paralleled the Unprecedented Increase of Invasive Group A Streptococcal Infection From 2022 to 2023

BACKGROUND

An unprecedented increase in pediatric invasive group A streptococcal (iGAS) infections was observed in most countries, including Iceland, in early 2023. The reasons for this rise are largely unknown. The aim of the study was to describe the parallel between nasopharyngeal (NP) carriage of group A streptococcal (GAS) in Icelandic children and the incidence of invasive disease.

METHODS

Electronic health records were used to identify children admitted to the Children's Hospital, Iceland, with iGAS. NP samples from asymptomatic children were collected for culture in February and March 2023 in 15 day-care centers in the greater Reykjavik area. Invasive and noninvasive isolates were characterized using whole genome sequencing. The results of the NP carriage were compared with data from 2009 to 2020.

RESULTS

Twenty-one children were diagnosed with iGAS from December 2022 to April 2023. Empyema, necrotizing fasciitis and septic or toxic shock were the most common clinical presentations. All the children were hospitalized; none died, but 9 needed intensive care. Pediatric iGAS infections increased 8-fold from a mean of 2.0/100.000 for 1975 to 2022 to 16.5/100.000 in early 2023. Asymptomatic NP GAS carriage among healthy children increased 3.5-fold from 8.0% from 2009 to 2020 to 28.5% in early 2023. Close genetic relatedness was found between carriage and invasive strains.

CONCLUSIONS

The significant rise of NP GAS carriage observed in early 2023 likely contributed to the simultaneous increased incidence of iGAS. With surveillance data, microbiological culture and molecular typing, genetic similarities between invasive disease isolates and NP isolates characteristics were confirmed.

Development of Streptococcus pyogenes pneumnonia and pleural empyema post-chickenpox infection in a 5-year-old child: A case report

Background

The introduction of the varicella vaccine has led to a significant decrease in pediatric varicella-induced invasive Streptococcus pyogenes (group A streptococcal [GAS]) infections. However, the development of a pleural empyema following a chickenpox infection is a rare complication in pediatric patients.

Case presentation

In this report, we present a 5-year-old male patient who presented to the emergency department with a deteriorating course two days after a chickenpox infection. The patient complained of high-grade documented fever, a congested throat, abdominal pain, shortness of breath, and most importantly, decreased air entry on the right side of the chest, along with the presence of crepitations. Such a deteriorated clinical picture suggested the presence of an infectious cause. The patient's physical examination and radiological imaging provided evidence for the presence of lower right-sided lobar pneumonia. On the second day of hospitalization, the patient showed worsening respiratory distress, prompting further investigations that confirmed the development of a right-sided pleural empyema through radiological imaging. Pediatric surgery consultation was requested, and 500 cc of pus was drained following the insertion of a chest tube, which was later sent for analysis. The patient's clinical picture improved significantly following this intervention. Due to the severity of his condition, the patient was transferred to the pediatric intensive care unit (PICU) for close monitoring. After one night in the PICU, during which his condition stabilized and oxygen therapy was gradually weaned off, the patient continued to improve on the general ward. Daily assessments and laboratory tests showed decreasing inflammatory markers and resolution of symptoms. Following three days of admission and confirmation of no underlying immunologic deficiency, the patient was discharged home with appropriate antibiotic therapy and follow-up instructions.

Discussion

Similar cases have been sporadically documented in pediatric literature, with notable examples involving older patients. The pathophysiology involves complex immune interactions and virulence factors of GAS, contributing to severe outcomes such as pleural effusion.

Conclusion

In this case, the 5-year-old patient experienced a severe progression from chickenpox to pleural empyema but ultimately improved following prompt medical intervention and chest tube drainage. The patient was discharged after a successful recovery, highlighting the efficacy of early recognition and treatment in managing such complications.

Are Invasive Group A Streptococcal Infections Preventable by Antibiotic Therapy?: A Collaborative Retrospective Study

BACKGROUND

In winter 2022/2023, a resurgence of invasive group A streptococcal (iGAS) infections in children was observed in Europe, including Germany and Switzerland. While a simultaneous increase in consultations for scarlet fever and pharyngitis was reported in England, leading to the recommendation to treat any suspected GAS disease with antibiotics, guidelines in Germany and Switzerland remained unchanged. We aimed to investigate whether this policy was appropriate.

METHODS

We conducted a retrospective multicenter study of children hospitalized for invasive GAS disease between September 2022 and March 2023 in pediatric departments in Dresden and Berlin (Germany) and Basel (Switzerland). We reviewed medical records and conducted structured telephone interviews to analyze whether suspected GAS infections with or without antibiotic treatment were reported prehospitalization.

RESULTS

In total, 63 patients met the inclusion criteria (median age 4.2 years, 57% males); however, clinical information was not complete for all analyzed characteristics; 32/54 (59%) had ≥1 physician visit ≤4 weeks prehospitalization. In 4/32 (13%) patients, GAS disease, that is, tonsillitis or scarlet fever, was suspected; 2/4 of them received antibiotics, and a positive rapid antigen test for GAS was documented in 1 of them.

CONCLUSIONS

A small minority of patients had suspected GAS infection within 4 weeks before iGAS disease. These data suggest that there is little opportunity to prevent iGAS disease by antibiotic therapy, because in most patients-even if seen by a physician-there was either no evidence of GAS disease or when GAS disease was suspected and treated with antibiotics, consecutive invasive GAS disease was not prevented.

Fifteen-minute consultation: Group A streptococcal pharyngitis, diagnosis and treatment in children

Group A streptococcus (GAS) is the most common bacterial cause of pharyngitis in children. GAS causes significant suppurative and non-suppurative complications including invasive GAS disease and acute rheumatic fever. This article describes the current epidemiology and clinical presentation of GAS pharyngitis and explores how diagnostic and treatment decisions differ globally. Several key decision support tools are discussed including international guidelines, clinical decision scores and laboratory tests along with the evidence for treatment choice and duration. With recent international reports describing an increase in GAS infections, clinicians should be familiar with their local GAS pharyngitis guidelines and the rationale for diagnosis and treatment of this common childhood illness.

Global Streptococcus pyogenes strain diversity, disease associations, and implications for vaccine development: a systematic review

The high strain diversity of Streptococcus pyogenes serves as a major obstacle to vaccine development against this leading global pathogen. We did a systematic review of studies in PubMed, MEDLINE, and Embase that reported the global distribution of S pyogenes emm-types and emm-clusters from Jan 1, 1990, to Feb 23, 2023. 212 datasets were included from 55 countries, encompassing 74 468 bacterial isolates belonging to 211 emm-types. Globally, an inverse correlation was observed between strain diversity and the UNDP Human Development Index (HDI; r=-0·72; p<0·0001), which remained consistent upon subanalysis by global region and site of infection. Greater strain diversity was associated with a lower HDI, suggesting the role of social determinants in diseases caused by S pyogenes. We used a population-weighted analysis to adjust for the disproportionate number of epidemiological studies from high-income countries and identified 15 key representative isolates as vaccine targets. Strong strain type associations were observed between the site of infection (invasive, skin, and throat) and several streptococcal lineages. In conclusion, the development of a truly global vaccine to reduce the immense burden of diseases caused by S pyogenes should consider the multidimensional diversity of the pathogen, including its social and environmental context, and not merely its geographical distribution.

Clinical and molecular epidemiological features of critically ill patients with invasive group A Streptococcus infections: a Belgian multicenter case-series

BACKGROUND

Recent alerts have highlighted an increase in group A streptococcal (GAS) infections since 2022 in Europe and the United States. Streptococcus pyogenes can cause limited skin or mucosal disease, but can also present as severe invasive disease necessitating critical care. We performed a multicenter retrospective study of patients with GAS infections recently admitted to Belgian intensive care units (ICUs) since January 2022. We describe patient characteristics and investigate the molecular epidemiology of the S. pyogenes strains involved.

RESULTS

Between January 2022 and May 2023, a total of 86 cases (56 adults, 30 children) with GAS disease were admitted to critical care in the university hospitals of Leuven, Antwerp and Liège. We noted a strikingly high incidence of severe community-acquired pneumonia (sCAP) (45% of adults, 77% of children) complicated with empyema in 45% and 83% of adult and pediatric cases, respectively. Two-thirds of patients with S. pyogenes pneumonia had viral co-infection, with influenza (13 adults, 5 children) predominating. Other disease presentations included necrotizing fasciitis (23% of adults), other severe skin/soft tissue infections (16% of adults, 13% of children) and ear/nose/throat infections (13% of adults, 13% of children). Cardiogenic shock was frequent (36% of adults, 20% of children). Fifty-six patients (65%) had toxic shock syndrome. Organ support requirements were high and included invasive mechanical ventilation (77% of adults, 50% of children), renal replacement therapy (29% of adults, 3% of children) and extracorporeal membrane oxygenation (20% of adults, 7% of children). Mortality was 21% in adults and 3% in children. Genomic analysis of S. pyogenes strains from 55 out of 86 patients showed a predominance of emm1 strains (73%), with a replacement of the M1global lineage by the toxigenic M1UK lineage (83% of emm1 strains were M1UK).

CONCLUSIONS

The recent rise of severe GAS infections (2022-23) is associated with introduction of the M1UK lineage in Belgium, but other factors may be at play-including intense circulation of respiratory viruses and potentially an immune debt after the COVID pandemic. Importantly, critical care physicians should include S. pyogenes as causative pathogen in the differential diagnosis of sCAP.

State-of-the-art of invasive Group A Streptococcus infection in children: protocol for a scoping review of the literature with a focus on predictors of invasive infection

Background: Invasive group A streptococcus infection (iGAS) is a serious, sometimes life-threatening condition, with high case fatality rates and high morbidity whose incidence is greatly increased in the last years. Despite the increasing importance and frequency of this condition, at the best of our knowledge, no previous reviews have been published focusing on the risk factors for the development of this condition and its early clinical features. This paper reports the study protocol for a scoping review that aims to analyze the early signs and clinical features of invasive group A streptococcus disease in children, to recognize the prodromal stage of the disease. Methods: Comprehensive research combining the terms pediatric and invasive group A streptococcus infection has been performed on PubMed and SCOPUS to identify potential eligible studies. The search strategy for PubMed will be available in this paper. Two reviewers will screen first the abstract and subsequently the full text to identify eligible articles according to the predefined inclusion criteria. Divergences between the reviewers will be resolved by discussion (with a third author if necessary). Two review authors will extract data independently, everyone on a different Excel spreadsheet. Each researcher will be blinded to the decision of the other researcher. When the process will be completed, in case of discordance, any disagreement will be identified and resolved through discussion (with a third author if necessary). Dissemination: The findings of this review will be published in a peer-reviewed journal.

Group A streptococcal disease in paediatric inpatients: a European perspective

Group A streptococcal (GAS) disease shows increasing incidence worldwide. We characterised children admitted with GAS infection to European hospitals and studied risk factors for severity and disability. This is a prospective, multicentre, cohort study (embedded in EUCLIDS and the Swiss Pediatric Sepsis Study) including 320 children, aged 1 month to 18 years, admitted with GAS infection to 41 hospitals in 6 European countries from 2012 to 2016. Demographic, clinical, microbiological and outcome data were collected. A total of 195 (61%) patients had sepsis. Two hundred thirty-six (74%) patients had GAS detected from a normally sterile site. The most common infection sites were the lower respiratory tract (LRTI) (22%), skin and soft tissue (SSTI) (23%) and bone and joint (19%). Compared to patients not admitted to PICU, patients admitted to PICU more commonly had LRTI (39 vs 8%), infection without a focus (22 vs 8%) and intracranial infection (9 vs 3%); less commonly had SSTI and bone and joint infections (p < 0.001); and were younger (median 40 (IQR 21-83) vs 56 (IQR 36-85) months, p = 0.01). Six PICU patients (2%) died. Sequelae at discharge from hospital were largely limited to patients admitted to PICU (29 vs 3%, p < 0.001; 12% overall) and included neurodisability, amputation, skin grafts, hearing loss and need for surgery. More patients were recruited in winter and spring (p < 0.001).

CONCLUSION

In an era of observed marked reduction in vaccine-preventable infections, GAS infection requiring hospital admission is still associated with significant severe disease in younger children, and short- and long-term morbidity. Further advances are required in the prevention and early recognition of GAS disease.

WHAT IS KNOWN

• Despite temporal and geographical variability, there is an increase of incidence of infection with group A streptococci. However, data on the epidemiology of group A streptococcal infections in European children is limited.

WHAT IS NEW

• In a large, prospective cohort of children with community-acquired bacterial infection requiring hospitalisation in Europe, GAS was the most frequent pathogen, with 12% disability at discharge, and 2% mortality in patients with GAS infection. • In children with GAS sepsis, IVIG was used in only 4.6% of patients and clindamycin in 29% of patients.

Prognostic factors for streptococcal toxic shock syndrome: systematic review and meta-analysis

OBJECTIVES

To quantify the prognostic effects of demographic and modifiable factors in streptococcal toxic shock syndrome (STSS).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE and CINAHL from inception to 19 September 2022, along with citations of included studies.

ELIGIBILITY CRITERIA

Pairs of reviewers independently screened potentially eligible studies of patients with Group A Streptococcus-induced STSS that quantified the association between at least one prognostic factor and outcome of interest.

DATA EXTRACTION AND SYNTHESIS

We performed random-effects meta-analysis after duplicate data extraction and risk of bias assessments. We rated the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

One randomised trial and 40 observational studies were eligible (n=1918 patients). We found a statistically significant association between clindamycin treatment and mortality (n=144; OR 0.14, 95% CI 0.06 to 0.37), but the certainty of evidence was low. Within clindamycin-treated STSS patients, we found a statistically significant association between intravenous Ig treatment and mortality (n=188; OR 0.34, 95% CI 0.15 to 0.75), but the certainty of evidence was also low. The odds of mortality may increase in patients ≥65 years when compared with patients 18-64 years (n=396; OR 2.37, 95% CI 1.47 to 3.84), but the certainty of evidence was low. We are uncertain whether non-steroidal anti-inflammatory drugs increase the odds of mortality (n=50; OR 4.14, 95% CI 1.13 to 15.14; very low certainty). Results failed to show a significant association between any other prognostic factor and outcome combination (very low to low certainty evidence) and no studies quantified the association between a prognostic factor and morbidity post-infection in STSS survivors.

CONCLUSIONS

Treatment with clindamycin and within clindamycin-treated patients, IVIG, was each significantly associated with mortality, but the certainty of evidence was low. Future research should focus on morbidity post-infection in STSS survivors.

PROSPERO REGISTRATION NUMBER

CRD42020166961.

Group A streptococcal bacteraemia at a tertiary hospital in Melbourne: concern of an under-reported risk group in Australia

BACKGROUND

Invasive group A streptococcal (iGAS) infections are increasing worldwide with at-risk groups being children, pregnant women and the elderly. In 2017, there was a rise in iGAS cases in Victoria, prompting a Chief Health Officer advisory.

AIMS

To describe the characteristics of patients with GAS bacteraemia admitted to a tertiary hospital. To compare at-risk groups in our population with those identified in the Victorian Government health alert.

METHODS

Retrospective review of patients with GAS bacteraemia admitted between June 2014 and December 2017 at a tertiary hospital in Melbourne, Victoria.

RESULTS

Forty-three cases of GAS bacteraemia occurred. Average age was 52 years (range 15-88 years) with 63% male. Average length of stay was 14 days (range 0-72 days) and all-cause mortality occurred in two (5%) cases. Twelve (28%) patients presented with shock, 11 (26%) required intensive care unit admission and 13 (30%) surgical intervention. A history of intravenous drug use was documented in 18 (42%) cases and was commonly complicated by bone or joint involvement or thrombosis. Typing of GAS samples identified 22 different emm-types.

CONCLUSION

GAS bacteraemia resulted in significant morbidity and prolonged hospitalisation. In contrast to the at-risk groups identified in the Victorian Government health advisory, the commonest risk group in this series were people who inject drugs and most commonly middle-aged men. Invasive GAS should be considered if a person who injects drugs presents with acute severe sepsis.

Morbidity and mortality in critically ill patients with invasive group A streptococcus infection: an observational study

Background

Group A streptococci (GAS) are known to cause serious invasive infections, but little is known about outcomes when patients with these infections are admitted to intensive care. We wanted to describe critically ill patients with severe sepsis or septic shock due to invasive GAS (iGAS) and compare them with other patients with severe sepsis or septic shock.

Methods

Adult patients admitted to a general intensive care unit (ICU) in Sweden (2007–2019) were screened for severe sepsis or septic shock according to Sepsis 2 definition. Individuals with iGAS infection were identified. The outcome variables were mortality, days alive and free of vasopressors and invasive mechanical ventilation, maximum acute kidney injury score for creatinine, use of continuous renal replacement therapy and maximum Sequential Organ Failure Assessment score during the ICU stay. Age, Simplified Acute Physiology Score (SAPS 3) and iGAS were used as independent, explanatory variables in regression analysis. Cox regression was used for survival analyses.

Results

iGAS was identified in 53 of 1021 (5.2%) patients. Patients with iGAS presented a lower median SAPS 3 score (62 [56–72]) vs 71 [61–81]), p <  0.001), had a higher frequency of cardiovascular cause of admission to the ICU (38 [72%] vs 145 [15%], p <  0.001) and had a higher median creatinine score (173 [100–311] vs 133 [86–208] μmol/L, p <  0.019). Of the GAS isolates, 50% were serotyped emm1/T1 and this group showed signs of more pronounced circulatory and renal failure than patients with non-emm1/T1 (p = 0.036 and p = 0.007, respectively). After correction for severity of illness (SAPS 3) and age, iGAS infection was associated with lower mortality risk (95% confidence interval (CI) of hazard ratio (HR) 0.204–0.746, p <  0.001). Morbidity analyses demonstrated that iGAS patients were more likely to develop renal failure.

Conclusion

Critically ill patients with iGAS infection had a lower mortality risk but a higher degree of renal failure compared to similarly ill sepsis patients. emm1/T1 was found to be the most dominant serotype, and patients with emm1/T1 demonstrated more circulatory and renal failure than patients with other serotypes of iGAS.

Clinical Description and Outcomes of Australian Children With Invasive Group A Streptococcal Disease

BACKGROUND

Invasive group A streptococcal disease is a severe infection with a high case fatality rate, estimated to cause more than 150,000 deaths per year worldwide. The clinical presentation of this infection is variable, and early diagnosis can be challenging. There are few data on its short- and longer-term outcomes, especially in children. The aim of this study was to assess the clinical presentation, management and short- and longer-term outcomes of invasive group A streptococcal disease in children in Australia.

METHODS

We undertook a prospective surveillance study of children with laboratory-confirmed invasive group A streptococcus disease admitted to 7 sentinel tertiary and quaternary pediatric hospitals in Australia between July 2016 and June 2018. We collected demographic and clinical data and contacted patients 6 months after discharge to assess longer-term outcomes.

RESULTS

We enrolled 181 children, 7 days to 16 years of age. The principal site of invasive infection was blood (126 children, 69.6%), and the most frequent clinical presentation was pneumonia in 46 children (25.4%). Twenty-six children developed streptococcal toxic shock syndrome (14.4%), and 74 had severe disease (40.9%), including 71 admitted to the intensive care unit. Five children died (2.8%). At discharge and 6 months, 29.3% and 15.2% of the children had persisting health problems, respectively.

CONCLUSIONS

Invasive group A streptococcal infection in Australian children is frequently severe and has a high long-term morbidity burden, highlighting the need for strengthened clinical care pathways, epidemiologic surveillance and prevention strategies.

Invasive Group A Streptococcus Infection in Children in Southern Israel Before and After the Introduction of Varicella Vaccine

The annual rates of group A Streptococcus bacteremia per 100 000 children in southern Israel declined after introduction of the varicella vaccine to the national immunization program, from 2.43 (95% confidence interval, 1.73-3.13) in 1995-2002 to 1.30 (95% confidence interval, 0.91-1.72) in 2010-2016 (P = .04). This reduction correlated with the disappearance of varicella rash as a predisposing factor.

Molecular Characterization of Streptococcus pyogenes Causing Invasive Disease in Pediatric Population in Spain A 12-year Study

OBJECTIVES

To perform a comprehensive description of the epidemiology of Streptococcus pyogenes invasive disease in the pediatric population in 2 regions of Spain (Catalonia and Gipuzkoa) through 12 years.

METHODS

All S. pyogenes isolates causing invasive disease in pediatric patients between 2005 and 2016 were included. The emm-type and the presence of 13 exotoxin genes (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa and slo) were determined in all 93 available isolates and the Multi Locus Sequece Typing in 10% of isolates of each different emm-type.

RESULTS

Overall, 103 cases of S. pyogenes invasive infections were detected: 77 in Catalonia and 26 in Gipuzkoa, being 50.5% females. The incidence rate per 100,000 children was 2.5 for Gipuzkoa and 2.6 for Catalonia, with no significant temporal trends. The median age was 30 months. The most frequent clinical presentations were: pneumonia (26.2%), bacteremia/sepsis (23.3%), septic arthritis/osteomyelitis (22.3%), cellulitis/mastoiditis (12.6%) and meningitis (6.8%). Eight children developed streptococcal toxic shock syndrome. Nine cases were preceded by varicella infection. The associated mortality rate was 3.9%. Three isolates were resistant to erythromycin, being one of them also resistant to clindamycin and 4 isolates were resistant to levofloxacine. Forteen different emm-types were detected being emm1/ST28 (40.9%) the most frequent clone in both regions followed by emm12/ST36-ST242, emm6/ST382, emm3/ST15, emm75/ST150 and emm4/ST38-39. speA gene was only detected in emm1 and emm3 isolates. Eight exotoxins were enough to assign an emm-type with a very high degree of accuracy (95%). The 30-valent vaccine would include 96.8% of isolates.

A multi-center clinical investigation on invasive Streptococcus pyogenes infection in China, 2010-2017

Background

Invasive S. pyogenes diseases are uncommon, serious infections with high case fatality rates (CFR). There are few publications on this subject in the field of pediatrics. This study aimed at characterizing clinical and laboratory aspects of this disease in Chinese children.

Patients and methods

A retrospective study was conducted and pediatric in-patients with S. pyogenes infection identified by cultures from normally sterile sites were included, who were diagnosed and treated in 9 tertiary hospitals during 2010–2017.

Results

A total of 66 cases were identified, in which 37 (56.1%) were male. The median age of these patients, including 11 neonates, was 3.0 y. Fifty-nine (89.4%) isolates were determined from blood. Fever was the major symptom (60/66, 90.9%) and sepsis was the most frequent presentation (64/66, 97.0%, including 42.4% with skin or soft tissue infections and 25.8% with pneumonia. The mean duration of the chief complaint was (3.8 ± 3.2) d. Only 18 (27.3%) patients had been given antibiotics prior to the hospitalization. Among all patients, 15 (22.7%) developed streptococcal toxin shock syndrome (STSS). No S. pyogenes strain was resistant to penicillin, ceftriaxone, or vancomycin, while 88.9% (56/63) and 81.4% (48/59) of the tested isolates were resistant to clindamycin and erythromycin respectively. Most of the patients were treated with β-lactams antibiotics and 36.4% had been treated with meropenem or imipenem. Thirteen (19.7%) cases died from infection, in which 9 (13.6%) had complication with STSS.

Conclusions

Invasive S. pyogenes infections often developed from skin or soft tissue infection and STSS was the main cause of death in Chinese children. Ongoing surveillance is required to gain a greater understanding of this disease.

Barriers and facilitators and the need for a clinical guideline for microbiological diagnostic testing in the hospital: a qualitative and quantitative study

The appropriate use of microbiological investigations is an important cornerstone of antibiotic stewardship programmes, but receives relatively limited attention. This study aimed to identify influencing factors in performing microbiological diagnostic tests and to assess the need for a clinical guideline. We performed a qualitative (focus group) and quantitative (online questionnaire survey) study among medical specialists and residents to identify physicians' considerations in performing microbiological diagnostic tests and to assess the need for a diagnostic guideline. The questionnaire consisted of 14 statements, divided into three categories: knowledge, influencing factors and presence of guidelines. The questionnaire was sent to physicians of the departments of internal medicine, intensive care, paediatrics and pulmonology in five hospitals in the Netherlands. Sub-analyses for medical specialists versus residents and for paediatric versus non-paediatric departments were performed. We included 187 completed questionnaires in our analyses. The physicians reported having adequate knowledge on methods, time-to-result and accuracy, but inadequate knowledge on costs of the tests. Patients' clinical condition, comorbidity, local guidelines and accuracy of tests were appraised as the four most important influencing factors to perform tests. Over 70% (132/187) of physicians reported being interested in a guideline for microbiological diagnostic testing. Fifteen physicians (8.0%) provided additional comments. This study identifies the influencing factors to microbiological testing and shows the demand for a clinical guideline among physicians. IMPORTANCE: Microbiological diagnostic tests are an important cornerstone within antibiotic stewardship programmes [1-5]. These programmes aim to ameliorate the appropriate use of antibiotics and thus improve clinical outcomes of infectious diseases, whilst reducing the emergence of antimicrobial resistance [6]. However, inappropriate microbiological testing is a widely recognised problem [7-12], and influencing factors to testing have not been studied in the past. Our research shows the demand for a clinical guideline among physicians, and it identifies their influencing factors to testing. These results can be used to create a clinical guideline for microbiological diagnostic testing, thus supporting antibiotic stewardship programmes and reducing antimicrobial resistance.

[Invasive disease due to Streptococcus pyogenes: Changes in incidence and prognostic factors]

INTRODUCTION

Invasive group A streptococcal disease (iGASD) is a serious infection in children. Several studies have shown an increased incidence in the past years.

OBJECTIVE

To evaluate the characteristics and outcome of iGASD in children, and to determine changes in incidence or severity.

MATERIAL AND METHODS

A retrospective study was conducted on children≤16 years evaluated in a tertiary paediatric hospital in Madrid, and diagnosed with iGASD (June 2005-July 2013). An analysis was made of the demographics, symptomatology, microbiology, and treatment. The changes throughout the period studied were evaluated, as well as parameters associated with disease severity.

RESULTS

The study included a total of 55 children with iGASD, with 33 (60%) females, and a median age of 48.5 (20.5-88.9) months. The most frequent clinical syndromes were cellulitis/subcutaneous abscess (21.8%), ENT abscess (20%), pneumonia (16.4%), osteoarticular infection (16.4%), and mastoiditis (12.7%). The incidence of iGASD (cases/10⁵ emergencies/year) increased from 5.6 (4.2-7.2) between June 2005-May 2009 to 18.9 (15.1-26) between June 2009-May 2013; P=.057. Surgery and admission to PICU was required by 35 (63.6%) and 10 (18.2%) patients, respectively. Children in PICU were younger (26.5 vs 52.6 months, P=.116), had a higher C-reactive protein (24.5 vs 10.7mg/dl, P<.001) and higher frequency of pneumonia (60 vs 7%, P<.001). In the multivariate analysis, only C-reactive protein was a risk factor for admission to PICU (OR: 1.14 [1.004-1.286], P=.04). There were no sequelae.

CONCLUSIONS

An increased incidence of iGASD was observed in the children in this study. Lower age, pneumonia, and higher C-reactive protein were associated with disease severity in this series.

Necrotizing Fasciitis: An Overview and 2 Illustrative Cases

Necrotizing fasciitis is the generic term for a series of progressive gangrenous infections of the skin and subcutaneous tissues. Typically, necrotizing fasciitis start with an, often small, infected lesion with atypical symptoms, which then quickly develops into a rapidly spreading, massive infection. The primary therapy is excision of all necrotic tissue in combination with treatment of systemic symptoms such as shock. The defects resulting from rigorous excision are often very large. Once they are clean, they require closure with an autograft. This article reviews the symptoms and treatment of necrotizing fasciitis. In addition, it illustrates, with 2 cases, how a hyaluronic-based extracellular matrix can be used to "fill in" with neodermis for the lost dermis and can create a wound bed most suitable for grafting.

Clinical Characteristics of Nosocomial Bloodstream Infections in Neonates in Two Hospitals, China

BACKGROUND

The improvement of medical condition requires prolonged hospital stays, which increase the risk of nosocomial bloodstream infections (BSIs).

METHODS

All nosocomial BSI newborns in two hospitals were included, and the demographic and clinical characteristics of bacteremia patients were obtained from the information systems. Isolates were identified by biochemical assays. Antimicrobial susceptibility was determined using disk diffusion method.

RESULTS

Except for three same risk factors, intubation with mechanical ventilation was a risk factor in Chongqing, while low birth weight was a risk factor in Henan. Klebsiella pneumoniae was the predominant strain in Chongqing, and Escherichia coli was the most prevalent strain in Henan. The resistance rate of gram-negative bacteria in Henan was higher than that of strains in Chongqing.

CONCLUSIONS

The risk factors and resistance rate of pathogens were different in different areas. Therefore, treatment protocols should be established based on the trends of drug resistance and bacterial spectrum.

Herpesviruses: Harmonious Pathogens but Relevant Cofactors in Other Diseases?

Most vertebrates are infected with one or more herpesviruses and remain so for the rest of their lives. The relationship of immunocompetent healthy host with herpesviruses may sometime be considered as harmonious. However, clinically severe diseases can occur when host immunity is compromised due to aging, during some stress response, co-infections or during neoplastic disease conditions. Discord can also occur during iatrogenic immunosuppression used for controlling graft rejection, in some primary genetic immunodeficiencies as well as when the virus infects a non-native host. In this review, we discuss such issues and their influence on host-herpesvirus interaction.

Prevalent emm Types among Invasive GAS in Europe and North America since Year 2000

BACKGROUND

Streptococcus pyogenes or group A streptococcus (GAS) is an important human pathogen responsible for a broad range of infections, from uncomplicated to more severe and invasive diseases with high mortality and morbidity. Epidemiological surveillance has been crucial to detect changes in the geographical and temporal variation of the disease pattern; for this purpose the M protein gene (emm) gene typing is the most widely used genotyping method, with more than 200 emm types recognized. Molecular epidemiological data have been also used for the development of GAS M protein-based vaccines.

METHODS

The aim of this paper was to provide an updated scenario of the most prevalent GAS emm types responsible for invasive infections in developed countries as Europe and North America (US and Canada), from 1st January 2000 to 31st May 2017. The search, performed in PubMed by the combined use of the terms ("emm") and ("invasive") retrieved 264 articles, of which 38 articles (31 from Europe and 7 from North America) met the inclusion criteria and were selected for this study. Additional five papers cited in the European articles but not retrieved by the search were included.

RESULTS

emm1 represented the dominant type in both Europe and North America, replaced by other emm types in only few occasions. The seven major emm types identified (emm1, emm28, emm89, emm3, emm12, emm4, and emm6) accounted for approximately 50-70% of the total isolates; less common emm types accounted for the remaining 30-50% of the cases. Most of the common emm types are included in either one or both the 26-valent and 30-valent vaccines, though some well-represented emm types found in Europe are not.

CONCLUSION

This study provided a picture of the prevalent emm types among invasive GAS (iGAS) in Europe and North America since the year 2000 onward. Continuous surveillance on the emm-type distribution among iGAS infections is strongly encouraged also to determine the potential coverage of the developing multivalent vaccines.

Invasive disease by Streptococcus pyogenes: patients hospitalized for 6 years

INTRODUCTION AND OBJECTIVE

The last years an increase of severe cases of invasive disease (ID) due to Streptococcus pyogenes or streptococcus b-hemolytic group A (SGA) had been detected. The aim of this study was to analyze the epidemiology and the clinical features of ID due to SGA in a tertiary Pediatric Hospital.

MATERIAL AND METHODS

Retrospective study in a Pediatric hospital, of all in-patients with final diagnosis of ID due to SGA during 6 years (2009-2014). To consider ID, SGA had to be isolated in sterile samples; in patients with fascitis necroticans in skin samples or in any sample in patients with the diagnostic of Streptococcal Toxic Shock Syndrome (STSS). The SSTS was defined as hypotension and at least 2 of these criteria: renal failure, hepatic failure, acute respiratory distress, tissue necrosis or desquamative erythematous rash. Demographic data, type of infection, risk factors, clinical presentation, analytical data at admission, treatment, need for admission to a pediatric intensive care unit, microbiological data, hospital stay and evolution were collected.

RESULTS

Fifty-two (52) cases were included (12/10,000 of all inpatients); 3 years-old was the medium age (p25-75: 1.4-6.9 years); 28 (53.8%) were boys. Fourteen patients (26.9%) had risk factors. Fever was the major symptom (51 patients, 98.1%). The skin lesions were the most frequent clinical manifestations found (21; 40.4%). In 50 (96%) cases, SGA was isolated in at least one sterile sample. Skin and soft tissue infections were diagnosed in 14 patients (26.9%), 14 (26.9%) pneumonias, 12 (23.1%) bones and joints infections, 10 (19.2%) SSTS, 6 (11.5%) occult bacteremia, 4 (7.7%) meningitis and 2 (3.8%) sepsis. Surgery was required in 18 cases (34.6%) and 17 patients (32.7%) needed intensive care. The medium hospital stay was 9.5 days (p25-75: 8-15 days). Three patients presented sequels and one patient died.

CONCLUSION

The ID due to SGA was a rare but serious reason for hospital admission. Skin and soft tissue infections, and pleuroneumonia were the most common forms of ID. The mortality of our sample was low despite the serious clinical manifestations.

High Incidence of Invasive Group A Streptococcal Infections in Remote Indigenous Communities in Northwestern Ontario, Canada

Background

Worldwide, indigenous populations appear to be at increased risk for invasive group A streptococcal (iGAS) infections. Although there is empirical evidence that the burden of iGAS disease is significant among remote First Nations communities in Northwestern Ontario, Canada, the epidemiology of iGAS infections in the area remains poorly characterized.

Methods

Individuals that met case definition for iGAS disease and whose laboratory specimens were processed by Meno Ya Win Health Centre in Sioux Lookout, Canada or who were reported to Thunder Bay District Health Unit, Canada were identified for the period 2009 to 2014. Case demographics, clinical severity, comorbidities, and risk factors were collected through chart review. Strain typing and antibiotic susceptibility were determined when possible. Basic descriptive statistics were calculated.

Results

Sixty-five cases of iGAS disease were identified, for an annualized incidence of 56.2 per 100 000. Primary bacteremia was present in 26.2% of cases, and cellulitis was identified in 55.4% of cases. The most common comorbidities identified were diabetes (38.5%) and skin conditions (38.5%). Prevalent risk factors included alcohol dependence (25%). Fourteen different emm types were identified among 42 isolates, with the most common being emm114 (17.4%), emm11 (15.2%), and emm118 (13.0%). Resistance to erythromycin and clindamycin was found in 24.6% of isolates.

Conclusions

Rural and remote First Nations communities in Northwestern Ontario experience iGAS infections at a rate 10 times the provincial and national average. Compared with other North American series, a lower proportion of isolates causing infection were of emm types included in candidate GAS vaccines.

The Association between Invasive Group A Streptococcal Diseases and Viral Respiratory Tract Infections

Viral infections of the upper respiratory tract are associated with a variety of invasive diseases caused by Streptococcus pyogenes, the group A streptococcus, including pneumonia, necrotizing fasciitis, toxic shock syndrome, and bacteremia. While these polymicrobial infections, or superinfections, are complex, progress has been made in understanding the molecular basis of disease. Areas of investigation have included the characterization of virus-induced changes in innate immunity, differences in bacterial adherence and internalization following viral infection, and the efficacy of vaccines in mitigating the morbidity and mortality of superinfections. Here, we briefly summarize viral-S. pyogenes superinfections with an emphasis on those affiliated with influenza viruses.

Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

Group A streptococcus (GAS) is an important cause of morbidity and mortality worldwide. Surveillance of emm types has important implications, as it can provide baseline information for possible implementation of vaccination. A total of 1,349 GAS pediatric isolates were collected during a 7-year period (2007 to 2013); emm typing was completed for 1,282 pharyngeal (84%) or nonpharyngeal (16%) isolates, and emm clusters and temporal changes were analyzed. Thirty-five different emm types, including 14 subtypes, were identified. The most prevalent emm types identified were 1 (16.7%), 12 (13.6%), 77 (10.9%), 4 (10.8%), 28 (10.4%), 6 (6.8%), 3 (6.6%), and 89 (6.6%), accounting for 82.3% of total isolates. Rheumatogenic emm types comprised 16.3% of total isolates. The emm types 12, 4, and 77 were more prevalent among pharyngeal isolates, and the emm types 1, 89, 6, 75, and 11 were more prevalent among nonpharyngeal isolates. The emm types identified belonged to 13 emm clusters, and the 8 most prevalent clusters comprised 97% of all isolates. There were statistically significant decreases in the prevalence of emm types 12, 4, 5, and 61 and increases in the prevalence of emm types 89, 75, and 11, compared with the period 2001 to 2006. The proposed 30-valent GAS vaccine, which is currently in preclinical studies, encompasses 97.2% of the emm types detected in our study and 97.4% of the erythromycin-resistant strains. In addition, it includes 93.3% of the emm types involved in bacteremia. A much greater diversity of GAS emm types was identified in our area than described previously. Seasonal fluctuations and the introduction of new emm types were observed. Continuous surveillance of emm types is needed in order to evaluate the possible benefits of an M protein-based GAS vaccine.

Group A streptococcal bacteremia without a source is associated with less severe disease in children

We analyzed characteristics of 86 Group A streptococcal bacteremia cases at Boston Children's Hospital from 1992 to 2012. Twenty-three percent of children had severe disease, using intensive care unit admission (18), disability (7) or death (2) as indicators. Children with bacteremia without a source (30% of cases) were less likely to have severe disease than children with focal infections in adjusted models.